Sparking plug for internal-combustion engines



C. BLANDIN. SPARKING PLUG FOR INTERNAL COMBUSTION ENGINES;

APPLICATION FILED SEPT, 21, I918.

Patented Nov. 2 1920-.--

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CHARLES BLANDIN, OF LYON, FRANCE.

SPARKING PLUG- FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Nov. 2, 1920.

Application filed September 21, 1918. Serial No. 255,096.

To all whom it may concern:

Be it known that I, CHAnLns BLANDIN, a citizen of the French Republic, residing at Lyon, France, have invented certain new and useful Improvements in Sparking Plugs for InternalU0mbustion Engines, of which the following is a specification.

This invention relates to a sparking plug for internal combustion engines wherein the central rod which constitutes one of the elec trodes is secured by a split nut having a double conical bore which, while imparting perfect air-tightness to the joint, secures the various parts of the sparking plug in position.

According to the present invention this nut is split longitudinally so that it can expand in its screw threaded socket.

Giving to its shape this nut cannot work loose even during the greatest vibrations of the motor, since by reason of its split construction vertical pressure is transformed into lateral pressure.

In the accompanying drawing- Figure l is a vertical section of one form of construction of the improved sparking plug. I

Figs. 2 and 3 show respectively in front elevation partly in section and in plan the split and double cone-shaped nut above referred to.

The sparking plug comprises the plug body proper a, of the ignition chamber 5 and a porcelain insulating member composed of two cones 0 and (Z holding the central rod 6 which forms an electrode.

A porcelain. body f is insulated from the porcelain body (Z by the double washer of mica 5/ which is tightened on to the asbestos packing i by the headed sleeve h screwed on the electrode rod 6, so that the central rod is fixed on a porcelain member outside the ignition chamber and consequently removed from the action of the hot gases and splashings of oil, which insures, both from the dielectric and thermic point of view, perfect insulation of the electrode without interfering with its use.

The porcelain cone 0 rests in the upper conic bore of the nut j. The porcelain cone (Z by entering into the conic lower bore of the split nut j (see Figs. 2 and 3) obliged the latter to open and press forcibly against the inner walls of the body of the sparking plug, thus securing perfect locking.

This feature of construction insures the absolute immovability of the porcelain parts forming the fixing device of the central rod while preventing them being broken under the tightening action.

Finally two nuts 70 render the porcelain part c immovable in its definite position.

What I claim as my invention and desire to secure by Letters Patent of the United States is 1. In a sparkingplug for internal combustion engines the combination of a cylindrical metal body having a part of reduced internal diameter at its lower end and internally screw threaded at its upper end, an electrode rod extending axially through said body, superposed porcelain insulating members within said metal body and surrounding said. rod, the uppermost of said bodies being conical, and a longitudinal split nut screwed into the upper end of said metal body and having a conical bore coacting with the conical surface of said conical body.

2. In a sparking plug for internal combustion engines, the combination of a cylindrical metal body having a part of reduced internal diameter at its lower end and internally screw threaded at its upper end, an electrode rod extending axially through said body, a porcelain insulating member within said metal body and having a. conical surface, a split nut screwed into the upper end of said metal body and having a double conical bore, a further inversely conical body engaging in said nut and locking nuts on the upper end of said electrode rod.

In. witness whereof I have signed this specification in the presence of two witnesses.

CHARLES BLANDIN.

Witnesses:

JEAN GERMAIN, J N0. W. Connrrr. 

